In this paper, the effect of the remaining coal pillars in a room and pillar section on the long wall face in the lower coal bed are tested by using equivalent material models. The failure laws of the overburden under...In this paper, the effect of the remaining coal pillars in a room and pillar section on the long wall face in the lower coal bed are tested by using equivalent material models. The failure laws of the overburden under coal pillars are discussed. A phenomenon of sub weighting has been observed when long wall face is in process under the remaining pillars in room and pillar mining section. It is concluded that, because coal pillars underwent a course of the stress increasing before they were fully destroyed, the existence of the coal pillars would shorten the distance of periodical weighting of the main roof in the long wall face. Based on this, the characteristic equations of the overburden movement under coal pillars are presented.展开更多
文摘In this paper, the effect of the remaining coal pillars in a room and pillar section on the long wall face in the lower coal bed are tested by using equivalent material models. The failure laws of the overburden under coal pillars are discussed. A phenomenon of sub weighting has been observed when long wall face is in process under the remaining pillars in room and pillar mining section. It is concluded that, because coal pillars underwent a course of the stress increasing before they were fully destroyed, the existence of the coal pillars would shorten the distance of periodical weighting of the main roof in the long wall face. Based on this, the characteristic equations of the overburden movement under coal pillars are presented.
